Ear tags to identify a particular animal and to provide information about the animal are in common use. As presently constituted, an ear tag is a plastic plate with a receiver in the form of a cup with an annular rib at its mouth. A stud, with a spear point with an undercut to provide a ledge engaging the cup rib, is pushed through the ear of the animal and into the cup, where it is held fast by the engagement of the annular rib and spear point ledge. Information about the animal is printed on the plate. For a discussion of such tags see, for example, U.S. Pat. No. 6,330,759. As the need for information has increased, the tags have become more complicated, and presently it has become desirable to present the information in the form of a barcode or an RFID (radio frequency identification) chip. To be fully useful, the barcode or RFID chip must be readable with commercial scanners. Typically, barcodes are black bars printed over a white substrate, because one of the requirements for reading a barcode is a large contrast between a bar and a substrate. The width of the bars and spaces is equally important. In order that the barcode carry the desired information reliably, the relationship of the bar and space width must be maintained. Any xe2x80x9cbleedingxe2x80x9d of the bar into a space can result in a misread or the production of faulty information.
In many instances, it is also desirable to have the tags differently colored, to add a quick and easy identification of groups of animals, for instance, to tell whether a litter of pigs was farrowed by a particular sow, or whether all the cattle in a particular feed lot or pen are from the same farm.
Currently, when the coded information on an animal tag is a barcode, several problems have arisen, such, for example, as that the bars have fuzzy edges and bleed into the spaces between the bars. This appears to the barcode reader as a wide bar rather than the desired narrow bar or as a narrow space rather than a wide space. This leads to misreads and/or faulty information. Another problem is a lack of contrast between the black bars and the panel color itself. When the bar code is printed directly onto the panel of the tag, the method of printing is generally not suitable to produce crisp, sharp images which can be read by a scanner easily and quickly.
In many cases, the tags remain on the animal for some considerable period of time. Even if the bar code can easily be read at the time of attachment, the information can fade with time, or can be rendered difficult to read as the tag experiences the normal wear and tear of everyday use. Although thin, clear plastic film overlays have been bonded to the tag to help prevent false readings, these films offer only limited protection. Young pigs, for example, which chew on anything in reach, can destroy such films, or thin tags in a short time.
One of the objects of this inventions is to provide a tag that can be color coded, that can be read quickly without misreads, and one that can remain attached to an animal for a long period of time without becoming illegible when scanned with a commercial barcode scanner.
Other objects will become apparent to those skilled in the art in the light of the following description and the accompanying drawing.
In accordance with this invention, generally stated, an animal tag is provided in the form of a durable, plastic tag of substantial thickness but transparent to a barcode reader. In the preferred embodiment, the tag has a pocket that is initially open al least one side, to receive a label. Although in the preferred embodiment, the label is a barcode label, the label can either carry a bar code and an RFID chip, or one of them. After a label is inserted into the pocket, the open edge or edges of the pocket are sealed, as by heat sealing, to form a water-tight cavity. The label, being separately printed, can display a barcode with clean, sharp bars and spaces, in contrasting black and white. The bar code can be read easily through the transparent walls of the panel, and the barcode will remain legible for long periods of time. Preferably the plastic of which the tag is made will contain UV absorbing material, and the label itself can contain or be coated with UV absorbing material to protect against damage from sunlight. Preferably, the label is made of vinyl and is relatively stiff, to facilitate its insertion into the pocket and to maintain its integrity, in case the plastic of which the tag is made is somewhat permeable to moisture. The label can be made in any color, and either a blank white area provided in the otherwise solid color label, to receive the bar code, or the bar code can be printed separately and adhered to the rest of the label. A barcode can be printed on either one or on both sides of the label. In another embodiment, the tag is made by a process of insert molding, in which the label is placed in a mold, and the mold is then filled around the label with the plastic that is transparent to the bar code reader. Alternatively, one wall of the transparent plastic can be placed in the mold, the label laid on it, and the second wall cast on the first, bonding to the first wall around the label. In yet another embodiment, one wall can be made with a shallow recess to receive the label, and the other wall, placed over the label and adhered or bonded to the first wall, or even heat sealed or otherwise sealed around the edges of the tag. In any case, the resultant tag has a barcode label encapsulated in a pocket. The embodiments in which the label is molded in the tag have the double advantage of not requiring the label to be inserted into a slot, and of forming a watertight seal without the additional step of heat sealing an open slot after the label is placed in the pocket. It has the disadvantage of requiring that all of the information carried by the bar code label be known and entered when the tag is made, whereas with the preferred embodiment, the bar code label can be printed substantially contemporaneously with the end use, and therefore, can easily be tailored to a particular animal or characteristic small group.